JP3349021B2 - Water jet propulsion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water jet propulsion device used as a propulsion device for a personal watercraft.

[0002]

2. Description of the Related Art A water jet propulsion device is used as a propulsion device in a boat such as a small personal watercraft for leisure. As such a water jet propulsion device, as shown in a vertical sectional view in FIG. 4, a fixed nozzle 22 for narrowing a flow path is provided at a rear end portion of a pump case 21 for accommodating a rotating impeller 20. At the rear end, for example, a tilt nozzle 24 is attached so as to be rotatable up and down via a horizontal support shaft 23, and a steering nozzle 26 is attached to the rear end of the tilt nozzle 24 so as to be rotatable left and right via a vertical support shaft 25. Are known (for example, Japanese Utility Model Application Laid-open No. 4-39).
No. 991).

[0005] Apart from this, as shown in a horizontal sectional view in FIG. 5, there is also known an arrangement in which a flow path is narrowed by a fixed nozzle 27 and a solid inner sphere 29 of a steering nozzle 28 disposed at a rear portion thereof. (Japanese Utility Model Laid-Open Publication No. 3-12695). The inner sphere 29 has a trumpet-shaped communication path 30 constituting the rear part of the flow path, and is supported by a shell-shaped outer sphere 32 via a vertical support shaft 31 so as to be rotatable left and right.

[0004]

However, as shown in FIG. 4, a tilt nozzle 24 rotatable up and down and a steering nozzle 26 rotatable left and right are attached to the rear of the fixed nozzle 22 for narrowing the flow path as shown in FIG. In this case, not only the number of parts of the nozzle is increased and the configuration is complicated, but also the overall length of the propulsion device is increased. Further, during a tilt operation in which the tilt nozzle 24 is tilted up and down, the high-speed jet accelerated by the fixed nozzle 22 is deflected by the tilt nozzle 24, so that a loss of thrust due to a change in momentum increases.

Further, as shown in FIG. 5, a structure in which the flow path is narrowed by the fixed nozzle 27 and the communication path 30 of the inner sphere 29 not only complicates the structure, but also makes the throttle flow path difficult at the time of steering. To tilt the inner sphere 29 that is a part to the left and right, the inner sphere 2
At the entrance side of the communication path 30 of No. 9, there is an enlarged portion 30a which largely protrudes from the opening of the fixed nozzle 27, and there is a possibility that the thrust may be reduced due to the pressure drop caused by this.

The present invention has been made in view of the above-mentioned conventional problems, and provides a water jet propulsion device capable of shortening the overall length, reducing the reduction in thrust at the time of tilt and steering, and reducing the number of components. The purpose is to:

[0007]

According to a first aspect of the present invention, there is provided a water jet propulsion device, wherein a spherical seat is provided at a rear end of a pump case accommodating a rotating impeller. Nozzle for narrowing the flow path through
And attached to the rear end of this tilt nozzle so that it can rotate left and right.
A tilted nozzle.
Is mounted on the rear end of the pump case so as to be vertically rotatable.

According to a second aspect of the present invention, there is provided a water jet propulsion device, wherein a spherical seat is provided on an outer peripheral surface of a rear end portion of a pump case accommodating a rotating impeller, and a tilt for narrowing a flow path through the spherical seat is provided. Nozzle and the rear end of this tilt nozzle
With the steering nozzle mounted to be able to rotate left and right
The tilt nozzle is attached to the rear end of the pump case so as to be vertically rotatable, and the rear end of the spherical seat is
The tilt nozzle is set rearward of the pivot point of the tilt nozzle along the axial direction of the pump case.

[0009]

According to the water jet propulsion device of the first aspect, the flow path is narrowed through the spherical seat at the rear end of the pump case.
Since the tilt nozzle is mounted to be vertically rotatable, the jet deflected by the rotation of the tilt nozzle is accelerating and is slower than the jet in the conventional tilt nozzle and steering nozzle. A decrease in thrust due to a change in momentum due to deflection is reduced. Further, the overall length is shortened, and the number of parts can be reduced.

Further, according to the water jet propulsion device of the present invention, the tilt nozzle is vertically rotatably mounted on the spherical seat provided on the outer peripheral surface of the rear end portion of the pump case. , which are set to the rear than the pivot point of the tilt nozzles, also it corresponds increasing the inclination angle in the tilt operation for tilting the tilting nozzle up and down, without tilting the nozzle deviates from a spherical seat, tilting nozzle it is possible to prevent pressure drop in <br/> Le, to prevent the foreign matter such as sand enters between the spherical seat and the tilt Bruno <br/> nozzle, Ji
It is possible to rotate the belt nozzle.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention. In FIG. 1, a water jet propulsion device 1 is a propulsion device attached to, for example, a bottom of a personal watercraft, in which an impeller 2 is connected via a spline to a shaft 35 that is rotationally driven by an engine (not shown). The impeller 2 is housed in a cylindrical pump case 3. The pump case 3 includes a boss 37 having a built-in bearing 36 for supporting a shaft 45 to which an impeller is screwed, and a vane (stationary vane) 3 formed on the outer periphery of the boss 37.
8 and is fixed to the hull by mounting means such as bolts (not shown). Below the pump case 3, a pump cover 39 forming a part of the ship bottom is provided with bolts 4.
0 is attached.

An inlet (not shown) for taking in water W is formed at the front of the pump case 3. Pump case 3
On the outer peripheral surface of the rear end, a convex curved spherical seat 4 having a spherical center O on the axis L of the pump case 3 is formed, and a tilt nozzle 5 of the pump case 3 It is rotatably attached to the rear end.

That is, the tilt nozzle 5 has its front inner surface slidably fitted to the spherical seat 4 and passes through the spherical center O of the spherical seat 4 with respect to the axis L of the pump case 3. It is supported by the spherical seat 4 via a pair of left and right horizontal support shafts 6, 6 (FIG. 2) located on a vertical horizontal axis, and is rotatable up and down. The tilt nozzle 5 constitutes a throttle passage for accelerating water W taken into the pump case 3 from the intake port by the impeller 2 and jetting the water W to the rear. An annular seal member 7 is attached to the surface of the spherical seat 4 to prevent the pressure of the jet from leaking from a contact portion with the tilt nozzle 5.

When the tilt nozzle 5 is in a horizontal position, its front end 5a is positioned so as not to be located forward of the pivot point 0.
For example, the tilt nozzle 5 is set at the same position as the rotation center O, so that the front portion of the tilt nozzle 5 can be externally fitted to the spherical seat 4 without being divided into two.

The front end 4a of the spherical seat 4 is set so as to be located forward of the pivot point of the tilt nozzle 5, that is, the center O of the horizontal support shaft 6, along the axis L of the pump case 3. . On the other hand, the rear end 4b of the spherical seat 4 is set so as to be located rearward of the rotation viewpoint O, and as a result, the tilt nozzle 5 is set at 10 as shown by a chain line in FIG.
The front end 5a of the tilt nozzle 5, which is set at substantially the same position as the center O as described above, protrudes from the spherical seat 4 at the rear end of the pump case 3 even if it is turned up and down within the inclination angle range of about °. Thus, it is possible to prevent leakage of the jet pressure due to the protrusion and entry of foreign matter such as sand into the spherical seat 4. A plurality of stoppers 41 are provided on the surface of the spherical seat 4 in the circumferential direction to restrict the tilt nozzle 5 from tilting by a predetermined angle or more.

A steering nozzle 8 is attached to the rear end of the tilt nozzle 5 so as to be rotatable left and right. That is, a steering nozzle 8 is supported at the rear end of the tilt nozzle 5 via a pair of vertical support shafts 9 and 9. In this embodiment, the horizontal support shaft 6 and the vertical support shaft 9 are formed by stepped bolts.

The tilt nozzle 5 and the steering nozzle 8 are connected to operating means on the upper part of the hull via operating members 42 and 43 such as push-pull cables shown in FIG. 3, respectively. , And the left and right rotation of the steering nozzle 8 can be remotely controlled.

Next, the operation of the above configuration will be described. For example, if the bow is in a raised position due to the movement of the center of gravity of the boat resulting from an increase in the number of crew members, it is necessary to start the boat with the bow lowered, but to correct this position, use an operation lever or the like. The tilt nozzle 5 is directed downward by remote control. As a result, the water W taken into the pump case 3 from the outside and pressurized by the impeller 2 is accelerated through the throttle flow path of the tilt nozzle 5 and then jetted downward, so that the bow is generated by the reaction force. It can be held down.

When the steering nozzle 8 is rotated left and right by remote control using an operation handle, the direction of water jetted through the steering nozzle 8 is changed left and right.
The hull turns.

In the water jet propulsion device 1, the tilt nozzle 5 that rotates up and down is a component that narrows the flow path, and the running water is accelerated in this flow path portion. The average velocity of the jet is lower than that of the accelerated jet in the tilt nozzle 24 or the steering nozzles 26 and 28 in the conventional example shown in FIGS. Therefore, even if the tilt nozzle 5 moves up and down, the decrease in thrust due to the change in momentum due to the vertical change of the jet flow is small.

In the above-described embodiment, the tilt nozzle 5 is rotatably fitted to the convex spherical seat 4 formed on the outer peripheral surface of the rear end of the pump case 3, but the present invention is not limited to this. 3, a concave spherical seat is formed on the inner peripheral surface of the rear end,
The front part of the tilt nozzle 5 may be rotatably fitted in the spherical seat.

[0022]

[0023]

As described in the foregoing, according to the invention of claim 1, a spherical seat provided at a rear end portion of the pump casing for housing the impeller, tilt nozzle narrowing the flow path through the spherical seat <br /> because Attach the rotatable Le to the pump casing, Ji
Since belt speed of the jet in the nozzle is relatively slow, decline of thrust is reduced by the rotation of the tilt Bruno <br/> nozzle. Further, the overall length is shortened, and the number of parts can be reduced.

According to the second aspect of the present invention, even if the tilt nozzle is moved up and down over the tilt angle range in the tilt operation, the engagement between the spherical seat and the tilt nozzle is sufficient. Biting and leakage of jet pressure can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a water jet propulsion device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG.

FIG. 3 is an external perspective view of the device.

FIG. 4 is a longitudinal sectional view of a conventional example.

FIG. 5 is a horizontal sectional view of another conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Water jet propulsion device, 2 ... Impeller, 3 ... Pump case, 4 ... Spherical seat, 5 ... Tilt nozzle, 5a ... Rotation viewpoint, 6 ... Horizontal support shaft, L ... Shaft center, O ... Rotation support

Claims (2)

(57) [Claims] 1. A pump case for accommodating a rotating impeller, a tilt nozzle connected to a rear end of the pump case for narrowing a flow path, and a left and right turn at the rear end of the tilt nozzle.
With a movably mounted steering nozzle ,
The water jet propulsion device, wherein the tilt nozzle is vertically rotatably attached to the pump case via a spherical seat provided at a rear end of the pump case. 2. A pump case for accommodating a rotating impeller, a tilt nozzle connected to a rear end of the pump case for narrowing a flow path, and a left and right turn at the rear end of the tilt nozzle.
With a movably mounted steering nozzle ,
The tilt nozzle is vertically rotatably attached to the pump case via a spherical seat provided on an outer peripheral surface of a rear end portion of the pump case, and a rear end of the spherical seat is
A water jet propulsion device that is set rearward of a pivot point of the tilt nozzle along an axial direction of the pump case.